1. Field
The invention relates to a light guide plate and a display device having the same. More, the invention relates to a light guide plate having improved light conversion efficiency with respect to a light incident thereto and a display device having the light guide plate.
2. Description of the Related Art
In general, a liquid crystal display device is operated using optical anisotropy and polarization of liquid crystals. Since liquid crystal molecules have a relatively thin and long structure, the liquid crystal molecules have directivity while being arranged. The arrangement direction of the liquid crystal molecules is controlled by applying an electric field to the liquid crystals.
That is, when the arrangement of the liquid crystal molecules is changed by the electric field, a light is refracted to correspond to the arrangement direction of the liquid crystal molecules due to the optical anisotropy of the liquid crystal molecules, thereby displaying an image.
The liquid crystal display device is manufactured by an array substrate manufacturing process in which a gate line, a data line, a thin film transistor and a pixel electrode are disposed in an array substrate, a color filter substrate manufacturing process in which a black matrix, a color filter and a common electrode are disposed in a color filter substrate, a cell process in which the array substrate and the color filter substrate are cut in the unit of a display cell after the array substrate is coupled to the color filter substrate and then the liquid crystals are injected between the array substrate and the color filter substrate to form a unit display panel, and a module process in which a driving integrated circuit (“IC”) and a printed circuit board are attached to the unit display panel and the unit display panel is assembled with a backlight unit to complete the liquid crystal display device.
In particular, the backlight unit is employed in the liquid crystal display device since the liquid crystal molecules of the liquid crystal display device are not self-emissive. The backlight unit includes a light source and is classified into a direct-illumination type backlight unit and an edge-illumination type backlight unit.
As the light source, a fluorescent lamp, such as a cold cathode fluorescent lamp, an external electrode fluorescent lamp, etc., is widely used, but the fluorescent lamp is being replaced with a light emitting diode since the light emitting diode has advantages of relatively low power consumption, light weight, high brightness, etc., when compared with the fluorescent lamp.
For the direct-illumination type backlight unit, lamps or light emitting diodes are disposed right under a liquid crystal display panel of a liquid crystal display device, and thus the light emitted from the lamps or the light emitting diodes are directly provided to the liquid crystal display panel. For the edge-illumination type backlight unit, a light guide plate is disposed under the liquid crystal display panel and the lamps or the light emitting diodes are disposed adjacent to one side surface of the light guide plate, and thus, the light emitted from the lamps or the light emitting diodes are provided to the liquid crystal display panel after being refracted and reflected by and passing through the light guide plate.